It seems to me when you consider that the NT was written by people who lived during the period that the Apostles walked the earth and these books were read by the Apostles, we should be even more confident in having Scripture as the rule of our faith.
Less a “rule” than testimony. The writings are not codified, and except for Romans not anything like systematic. Collections of apostolic writings. Revelation is the oddball. The Eastern Church did not include it until quite late, and most Christians lived in the East.
Apocalypse does not meet your criteria. This was read at the most by one apostle (if one considers John of Patmos to be the same as the Apostle John, but that’s doubtful)
What was the first book of the Bible?